What your thought of the recent demerger of SMM from SCI? It is good buy to retain the SCM share or sell?

I believe you are speaking from perspective of SCI holder?

For a long term play, probably keeping it is a good idea, since it is "technically" free. Offshore and marine is a cyclical industry, which may recover well after the recession.

For short term, SCM probably will face a downward pressure on price until they manage to stem its bleeding cashflow.